Coated article

ABSTRACT

To provide a plastic spectacle lens which has a very durable hard coat layer and primer layer and prevents the cracking and peeling off of the layer and a reduction in the hardness of the layer, and other coated articles. This coated article has a coat layer containing titanium oxide and an organic Co(II) compound on the surface of a substrate.

FIELD OF THE INVENTION

The present invention relates to an article coated with a resin film,particularly a coated plastic lens having a titanium oxide-containingresin coat layer, other coated articles and a composition for forming atitanium oxide-containing resin coat layer.

DESCRIPTION OF THE PRIOR ART

Since plastic spectacle lenses have such a defect that they are easilyscratched, a silicon-based resin or other hard coat layer has beenconventionally formed on the surface of a plastic lens substrate. Aprimer layer made from a resin such as an urethane-based resin has alsobeen formed between this hard coat layer and the surface of thesubstrate to improve the adhesion of the hard coat layer and the impactresistance of a plastic lens.

However, when a silicone-based hard coat layer is formed on ahigh-refractive resin lens having a refractive index of 1.50 or more, aninterference fringe is formed by the difference of refractive indexbetween the resin lens and the hard coat layer (or primer layer),thereby worsening the appearance of the lens. To solve this problem,JP-A 7-325201 and JP-A 10-332902 (the term “JP-A” as used herein meansan “unexamined published Japanese patent application”) propose theaddition of an oxide having a high refractive index such as titaniumoxide (TiO₂). (or a composite oxide containing TiO₂) to a hard coat orprimer to reduce the difference of refractive index between the hardcoat layer or primer layer and the substrate so as to prevent aninterference fringe.

JP-A 11-131021 discloses a composition for coating comprising thefollowing essential ingredients:

(A) a composite oxide fine particle of tin oxide, titanium oxide andzirconium oxide;

(B) a silane compound having at least one polymerizable reactive group;and

(C) an epoxy (meth)acrylate having a glycidyl group and (meth)acryloylgroup in one molecule at the same time.

In the above publication, a silanol or epoxy compound curing catalystmay be added and acetylacetonato containing. Co(II) as the center metalis enumerated as one example of the curing catalyst.

However, the hard coat layer or primer layer containing titanium oxidehas such problems as the cracking and peeling off of the layer and areduction in the hardness of the layer due to insufficient durability.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a coated articlewhich has a highly durable resin coat layer containing titanium oxideand prevents the cracking and peeling off of the layer and a reductionin the hardness of the layer.

It is another object of the present invention to provide a plastic lenswhich has a highly durable hard coat layer or primer layer and preventsthe cracking and peeling off of the layer and a reduction in thehardness of the layer.

It is still another object of the present invention to provide asolution composition for forming a hard coat layer for a plastic lens.

A further object of the present invention is attained by a solutioncomposition for forming a primer layer for a plastic lens.

Other objects and advantages of the present invention will becomeapparent from the following description.

Firstly, according to the present invention, the above objects andadvantages of the present invention are attained by a coated articlecomprising a substrate and a coat layer made from a resin compositioncontaining titanium oxide and an organic Co(II) compound and formed onthe surface of the substrate.

Secondly, according to the present invention, the above objects andadvantages of the present invention are attained by a plastic lens whichcomprises a plastic lens substrate having a refractive index of 1.50 ormore and a hard coat layer formed on the surface of the substratedirectly or through a primer layer, the hard coat layer comprising:

(1) 2 to 70 wt % of titanium oxide or a composite oxide thereof having aparticle diameter of 1.0 to 100 nm;

(2) 0.1 to 10 wt % of an organic Co(II) compound;

(3) 20 to 97.9 wt % of a silicon resin; and

(4) 0.001 to 10 wt % of a curing catalyst,

and having a refractive index of 1.48 or more and a thickness of 0.1 to5 μm, the weight percentages of the above components (1), (2) and (3)being based on 100 wt % of the total weight of the components (1), (2)and (3), and the weight percentage of the above component (4) beingbased on the total weight of the above components (1), (2) and (3).

Thirdly, the above objects and advantages of the present invention areattained by a plastic lens which comprises a plastic lens substratehaving a refractive index of 1.50 or more, a primer layer formed on thesurface of the substrate, and a hard coat layer comprising a siliconeresin as a resin component and formed on the surface of the primerlayer, the primer layer comprising:

(1) 2 to 70 wt % of titanium oxide or a composite oxide thereof having aparticle diameter of 1.0 to 100 nm;

(2) 0.1 to 10 wt % of an organic Co(II) compound; and

(3) 20 to 97.9 wt % of an urethane resin,

and having a refractive index of 1.48 or more and a thickness of 0.5 to5 μm, the weight percentages of the above components (1), (2) and (3)being based on 100 wt % of the total weight of the components (1), (2)and (3).

In the fourth place, according to the present invention, the aboveobjects and advantages of the present invention are attained by asolution composition for forming a hard coat layer which comprises:

(1) 2 to 70 wt % in terms of solid content of a sol containing titaniumoxide or a composite oxide thereof having a particle diameter of 1.0 to100 nm dispersed in water or an organic medium;

(2) 0.1 to 10 wt % of an organic Co(II) compound;

(3) 20 to 97.9 wt % of an epoxy group-containing silicon compoundrepresented by the following formula (1):

R¹R² _(a)Si(OR³)_(3−a)  (1)

wherein R₁ is a group having an epoxy group and 2 to 12 carbon atoms, R²is an alkyl group or halogenoalkyl group having 1 to 6 carbon atoms,alkenyl group having 2 to 6 carbon atoms, phenyl group or halogenophenylgroup, R³ is a hydrogen atom, alkyl group or acyl group having 1 to 4carbon atoms, and a is 0, 1 or 2,

or a partial hydrolysate thereof; and

(4) 0.001 to 10 wt % of a curing catalyst, the weight percentages of theabove components (1), (2) and

(3) being based on 100 wt % of the total weight of the components (1),(2) and (3), and the weight percentage of the above component (4) beingbased on the total weight of the above components (1), (2) and (3).

In the fifth place, according to the present invention, the aboveobjects and advantages of the present invention are attained by asolution composition for forming a primer layer comprising:

(1) 2 to 70 wt % in terms of solid content of a sol containing titaniumoxide or a composite oxide thereof having a particle diameter of 1.0 to100 nm dispersed in water or an organic medium;

(2) 0.1 to 10 wt % of an organic CO(II) compound;

(3) 10 to 87.9 wt % of a polyol; and

(4) 10 to 87.9 wt % of a polyisocyanate,

the weight percentages of the above components (1), (2), (3) and (4)being based on 100 wt % of the total weight of all the components.

The present invention will be described in detail hereinafter.

A description is first given of the coated article of the presentinvention.

The coat layer of the coated article is made from a resin compositioncontaining titanium oxide and an organic Co(II) compound.

Co(II) is characterized in that it has an absorption peak at awavelength of 420 to 550 nm and an organic compound having CO(III) withthe main absorption peak at a wavelength of 600 to 800 nm cannot be usedin the present invention because it does not have the effect of theorganic Co(II) compound of the present invention.

When the titanium oxide-containing resin coat layer contains an organicCo(II) compound and this coat layer is irradiated with ultraviolet raysfrom sunlight, fluorescent light or other light, ultraviolet rayscollide with a titanium oxide particle contained in the coat layer. Thetitanium oxide particle is excited by ultraviolet rays, thereby formingelectrons excited to a conduction band and electron holes having avalence band. The exited electrons and electron holes move toward apolymer in the coat layer, reach the polymer and try to cause an opticalcatalytic reaction there to decompose the polymer by dissociating abond, for example, a C—C bond in the polymer. When the organic Co(II)compound is existent in this coat layer, part of excited energy oftitanium oxide moves toward the organic Co(II) compound and is convertedinto heat. Thereby, the decomposition of the polymer is suppressed,thereby retarding the deterioration of the coat layer. As a result, theadhesion of the coat layer to the substrate is retained, the cracking ofthe coat layer hardly occurs, and the hardness of the coat layer ismaintained. Since the excitation energy of titanium oxide is about 3 eV,it is desired that a compound containing this metal ion should have anenergy gap corresponding to 2.1 to 2.8 eV in order to receive thisenergy efficiently. The wavelength of an optical absorption bandcorresponding to this energy gap is 420 to 550 nm. Therefore, an organicCo(II) compound having an optical absorption peak at 420 to 550 nm iseffective. However, it cannot be said that all compounds having thisenergy gap can receive this energy.

Preferably, the organic CO(II) compound having an absorption peak at awavelength of 420 to 550 nm used in the present invention dissolves in asolvent for a titanium oxide-containing resin coat layer, such as analcohol or propylene glycol ether, has compatibility with the resincomponent of the coat layer and does not impede the physical propertiesof the resin of the coat layer. Preferred examples of the compoundinclude the above Co(II) ion chelate compounds and fatty acid salts.

The ligand of the chelate compound is preferably what contains analiphatic chelate structure, as exemplified by acetylacetone,di-n-butoxide-mono-ethyl acetate, di-n-butoxide-mono-methyl acetate,methyl ethyl ketooxime, 2,4-hexanedione, 3,5-heptanedione andacetooxime. A preferred example of the chelate compound is cobalt (II)acetylacetonato.

Preferred examples of the acid of the fatty acid compound include2-ethyl-hexylic acid, stearic acid, lauric acid, oleic acid, aceticacid, sebacic acid, dodecane diacid, propionic acid, brassylic acid,isobutylic acid, citraconic acid and tetraethylene diamine tetraaceticacid. The fatty acid compound is, for example, a cobalt(II) salt of2-ethyl-hexylic acid.

Examples of the resin component of the resin coat layer in the presentinvention include silicon resin, urethane resin, acrylic resin,methacrylic resin, allyl resin, polyester resin, polycarbonate resin,epoxy resin and urethane acrylic resin. The resin coat layer containstitanium oxide and an organic Co(II) compound in addition to the aboveresin component. The amount of titanium oxide is preferably 2 to 70 wt %and the amount of the organic Co(II) compound is preferably 0.1 to 10 wt%. The resin coat layer preferably has a refractive index of 1.48 ormore. The amount of titanium oxide is more preferably 10 to 70 wt %, themost preferably 15 to 60 wt %. The amount of the organic Co(II) compoundis more preferably 0.2 to 5 wt %.

The above titanium oxide may have an amorphous structure but preferablya rutile, anatase or brookite crystal structure. Preferably, at least ½,that is, at least 50% of the amount of titanium oxide has at least oneof rutile, anatase or brookite crystal structures. Out of these crystalstructures, the rutile type is more preferred and at least ½, that is,50% of the amount of titanium oxide has a rutile type crystal structure.However, as rutile type titanium dioxide is more expensive than anatasetype titanium dioxide, anatase type titanium dioxide is preferably usedfrom an economical point of view. The titanium oxide may be a titaniumoxide fine particle or a composite oxide of titanium and at least oneelement selected from the group consisting of Si, Al, Sn, Sb, Ta, Ce,La, Fe, Zn, W, Zr and In. Examples of the composite oxide-include acomposite oxide fine particle of titanium and iron (TiO₂.Fe₂O₃),composite oxide fine particle of titanium and silicon (TiO₂.SiO₂),composite oxide fine particle of titanium and cerium (TiO₂.CeO₂),composite oxide fine particle of titanium, iron and silicon(TiO₂.Fe₂O₃.SiO₂), composite oxide fine particle of titanium, cerium andsilicon (TiO₂.CeO₂.SiO₂), composite oxide fine particle of titanium,zirconium and silicon (TiO₂.ZrO₂.SiO₂) and composite oxide fine particleof titanium, aluminum and silicon (TiO₂.Al₂.O₃.SiO₂).

The titanium oxide fine particle or titanium composite oxide fineparticle can be obtained by any known method. For example, a hydroustitanic acid gel or sol is prepared by adding an alkali to an aqueoussolution of a titanium salt such as titanium chloride or titaniumsulfate for neutralization or by passing an aqueous solution of atitanium salt through an ion exchange resin. Thereafter, hydrogenperoxide water is added to the hydrous titanic acid gel or sol, or amixture thereof to dissolve the hydrous titanic acid so as to prepare auniform aqueous solution. Further, titanic acid is hydrolyzed by heatingto obtain a titanium oxide sol containing titanium oxide dispersedtherein. In the step before the heat treatment, an inorganic compound ofone element or two or more elements selected from the group consistingof Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr and In is added to obtain acomposite oxide sol. For example, JP-A 63-185820 discloses a process forproducing a silica-titanium or titanium-silica-zirconia composite oxidesol.

Further, the surface of the above titanium oxide fine particle ortitanium composite oxide fine particle may be surface coated with (onelayer or two or more layers of) silicon oxide, a mixture of siliconoxide and an oxide of at least one element selected from the groupconsisting of Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr and In, or acomposite oxide. The fine particle can be obtained by any known method.For example, JP-A 8-48940 discloses a process for producing a compositeoxide sol by coating a titanium-silica composite oxide fine particlewith silica-zirconia composite oxide. When titanium oxide is existent inthe form of a composite oxide fine particle or surface coated fineparticle, the weight of a metal oxide other than titanium oxidecontained in the fine particle is excluded (ignored) in the calculationof the amount of titanium oxide.

The titanium oxide may be amorphous but preferably has an anatase orrutile crystal structure. Particularly preferably, the titanium oxidehas a rutile crystal structure.

When the titanium oxide is a composite oxide fine particle, to improveits dispersibility in a solvent, the surface of the composite oxide fineparticle can be modified by an organic silane compound or an amine. Theamount of the organic silane compound is 0 to 20 wt % based on theweight of the fine particle. This surface modification may be carriedout while an organic silane compound having a hydrolyzable group is nothydrolyzed or after it is hydrolyzed.

The organic silane compound for modifying the surface of the compositeoxide fine particle is, for example, an organic silane represented bythe formula R₃SiX, R₂SiX₂, RSiX₃ or SiX₄ (R is an organic group havingalkyl, phenyl, vinyl, methacryloxy, mercapto, amino, epoxy or ureide andX is a hydrolyzable group), such as trimethyl methoxysilane, diphenyldimethoxysilane, vinyl trimethoxysilane, γ-methacryloxypropyldimethylmethoxysilane, γ-aminopropyl triethoxysilane, glycidoxypropyltrimethoxysilane, γ-ureidepropyl triethoxysilane or tetraethylorthosilicate.

Examples of the amine for modifying the surface of the fine particleinclude alkylamines such as ammonium and ethylamine, aralkylamines suchas benzylamine, alicyclic amines such as piperidine and alkanolaminessuch as monoethanolamine.

To modify the surface of the fine particle with an organic siliconcompound or amine, for example, a composite oxide fine particle is mixedwith an alcohol solution of the compound, a predetermined amount ofwater and optionally a catalyst are added, and the resulting mixture isleft to stand at normal temperature for a predetermined time or heated.The surface of the composite oxide fine particle can be modified byadding a hydrolysate of the compound and a composite oxide fine particleto a mixture of water and an alcohol and by heating.

The resin coat layer of the present invention may contain an inorganicoxide, antioxidant, ultraviolet light absorber, leveling agent,lubricity modifier, antistatic agent, bluing agent and the like asrequired in addition to the above resin, titanium oxide and organicCo(II) compound. The inorganic oxide is an oxide or composite oxide ofat least one element selected from the group consisting of Si, Al, Sn,Sb, Ta, La, Zn, W, Zr and In and a fine particle having a particlediameter of 1 to 100 nm. The inorganic oxide may be contained in anamount of 0 to 70 wt % in terms of nonvolatile content.

The above antioxidant is preferably what has a sulfide structure (C—S—Cstructure), more preferably a hindered phenolic compound having asulfide structure. Examples of the antioxidant include4,4′-thiobis(3-methyl-6-t-butylphenol),2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate],2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine,didodecyl 3,3′-thiobispropionate, dibctadecyl 3,3′-thiobispropionate,dimyristyl 3,3′-thiobispropionate and2,4-[bis(octylthio)methyl]-O-cresol. The antioxidant is preferablycontained in an amount of 5 wt % or less.

The leveling agent or lubricity modifier is preferably a copolymer ofpolyoxyalkylene and polydimethylsiloxane or a copolymer ofpolyoxyalkylene and fluorocarbon. They are preferably used in an amountof 0.001 to 10 parts by weight based on the total amount of the coatingsolution.

The thickness of the resin coat layer in the present invention, whichdiffers according to the purpose of a resin coated article, ispreferably 0.10 to 10 μm.

The coated article of the present invention is produced by coating thesurface of the substrate with a coating solution for a resin coat layerby dip coating, spinner coating, spray coating or flow coating anddrying the coating. solution to form a film and heating the film thusformed on the surface of the substrate at a temperature lower than theheat resistant temperature of the substrate.

When an ultraviolet curable resin is used as a matrix component of thecoating solution for a resin coat layer, the coated article of thepresent invention can be produced by coating the surface ofthe'substrate with the coating solution and irradiating the surface ofthe substrate coated with the coating solution with ultravioletradiation having a predetermined wavelength to cure the resin.

The coated article of the present invention can be a plastic lens havinga hard coat layer directly on the surface of a substrate. In this case,the titanium oxide-containing resin coat layer in the present inventionis used as the hard coat layer. The coated article of the presentinvention can be a plastic lens having a primer layer and a hard coatlayer formed on the surface of a substrate in the order named. In thiscase, the titanium oxide-containing resin coat layer. of the presentinvention is used as either one or both of the primer layer and hardcoat layer.

A preferred mode of the titanium oxide-containing resin coat layer ofthe present invention is a hard coat layer of a titaniumoxide-containing silicon resin having a refractive index of 1.48 or moreand a thickness of 0.1 to 5 μm formed on the surface of the substrate ofa plastic lens having a refractive index of 1.50 or more directly orthrough a primer layer.

Another preferred mode of the titanium oxide-containing resin coat layerof the present invention is a primer layer of a titaniumoxide-containing urethane resin having a refractive index of 1.48 ormore and a thickness of 0.5 to 5 μm formed between the surface of thesubstrate of a plastic lens having a refractive index of 1.50 or moreand a hard coat layer of a silicon resin having a refractive index of1.48 or more formed thereon.

Still another preferred mode of the titanium oxide-containing resin coatlayer of the present invention is a combination of a primer layer and ahard coat layer in a plastic lens which comprises the surface of thesubstrate of a plastic lens having a refractive index of 1.50 or more, aprimer layer of a titanium oxide-containing urethane resin having athickness of 0.5 to 5 μm formed on the surface of the substrate and ahard coat layer of a titanium oxide-containing silicon resin having arefractive index of 1.48 or more and a thickness of 0.1 to 5 μm formedon the primer layer. That is, the titanium oxide-containing resin coatlayer of the present invention is used as the both layers.

The hard coat layer when the titanium oxide-containing silicon resincoat layer of the present invention is formed on the surface of aplastic lens substrate as a hard coat layer will be described in detailhereinafter.

HARD COAT LAYER

A coating solution (solution composition) for forming a silicone hardcoat layer will be described.

The coating solution for forming a hard coat layer comprises thefollowing components (1) to (4):

(1) 2 to 70 wt % in terms of solid content of a sol containing titaniumoxide or a composite oxide thereof having a particle diameter of 1.0 to100 nm dispersed in water or an organic medium;

(2) 0.1 to 10 wt % of an organic Co(II) compound;

(3) 20 to 97.9 wt % of an epoxy group-containing silicon compoundrepresented by the following formula (1):

R¹R² _(a)Si(OR³)_(3−a)  (1)

wherein R¹ is a group having an epoxy group and 2 to 12 carbon atoms, R²is an alkyl group or halogenoalkyl group having 1 to 6 carbon atoms,alkenyl group having 2 to 6 carbon atoms, or phenyl group orhalogenophenyl group, R³ is a hydrogen atom, alkyl group or acyl grouphaving 1 to 4 carbon atoms, and a is 0, 1 or 2,

or a partial hydrolysate thereof; and

(4) 0.001 to 10 wt % of a curing catalyst.

The components (1) and (2) have already been described above.

Examples of the epoxy group-containing silicon compound as the component(3) include γ-glycidoxypropyl trimethoxysilane, β-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyl triethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyl dimethoxysilane,γ-glycidoxypropylmethyl diethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

Examples of the curing catalyst (4) of the composition for forming ahard coat layer include alkali metal salts and ammonium salts ofcarboxylic acids, metal salts and ammonium salts of acetylacetone, metalsalts of ethyl acetoacetate, metal salts coordinated with acetylacetoneand ethyl acetoacetate, metal salt hydrates of ethylene diamine, primaryto tertiary amines, polyalkylene amines, sulfonates, magnesiumperchlorate, ammonium perchlorates, and combinations of these compoundsand organic mercaptan or mercaptoalkylenesilane. The curing catalyst maybe added when a composition for forming a hard coat layer is prepared orright before a composition for forming a hard coat layer is applied.

The weight percentages of the above components (1), (2) and (3) arebased on 100 wt % of the total weight of the components (1), (2) and(3), and the weight percentage of the above component (4) is based onthe total weight of the above components (1), (2) and (3).

The amount of the component (1) is preferably 5 to 60 wt %, the amountof the component (2) is preferably 0.2 to 5 wt %, and the amount of thecomponent (3) is preferably 35 to 94.8 wt %. The amount of the component(4) is preferably 0.01 to 8 wt %.

The coating solution for forming a hard coat layer may contain thefollowing components (D) and (E) as required in addition to the abovecomponents (1) to (4).

Component (D)

A fine particle of an oxide of at least one element selected from thegroup consisting of Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr and In,such as SiO₂, Al₂O₃, SnO₂, Sb₂O₅, Ta₂O₅, CeO, La₂O₃, Fe₂O₃, ZnO, WO₃,ZrO₂ or In₂O₃ in the form of a sol solution and having a particlediameter of 1.0 to 100 nm may be contained in a total amount of 80 wt %or less.

When the fine particle is a composite oxide, its surface may be modifiedby an organic silane compound or amine to improve its dispersibility ina solvent. It should be understood that surface modification iscompletely the same as that for a titanium composite oxide. When theabove titanium oxide is a titanium composite oxide, for example, aTiO₂—ZrO₂—SiO₂ composite oxide fine particle, a metal oxide other thantitanium oxide contained in the composite oxide, for example, zirconiumoxide and silicon oxide are the components (D).

The fine particle of the component (D) is preferably dispersed in wateror an organic solvent such as an alcohol in an amount of 5 to 80 wt %.The fine particle of the component (D) is contained in the coatingsolution for forming a hard coat layer in an amount of 70 wt % or lessin terms of solid content.

Component (E)

The component (E) is an antioxidant, preferably an antioxidant having aC—S—C structure as described above.

The following components (F-1) to (F-14) which can react with ahydrolyzed silanol group and epoxy group may be used to improve physicalproperties such as dyability, heat resistance, water resistance,antistatic properties and surface hardness or assist a catalyticfunction, in addition to the above components (A) to (E).

Component (F-1)

The component (F-1) is an organic compound having only one OH or SHgroup in the molecule, at least one group selected from the groupconsisting of —O—, —CO—O—, —S—, —CO—S— and —CS—S— in the molecular mainchain and further at least one unsaturated group and soluble in water ora lower alcohol having 4 or less carbon atoms.

The above compound is preferably a compound represented by the followingformula (2):

R⁴—X—R⁵YH (2)  (2)

wherein R⁴ is a monovalent hydrocarbon group having at least oneunsaturated group and may contain oxygen and sulfur atoms, R⁵ is adivalent hydrocarbon group having 2 or more carbon atoms and may containoxygen and sulfur atoms, and X and Y are each independently an oxygenatom or sulfur atom.

Examples of the compound represented by the above formula (2) includepolyethylene glycol monomethacrylate, poly(butanediol)monoacrylate,poly(butanediol)monomethacrylate, 1,4-butanediolmonovinyl ether,1,6-hexanedithiol monoacrylate, di(acryloxyethyl)hydroxyethylamine,2-hydroxy-3-phenoxypropyl acrylate, pentaerythritol triacrylate,2-hydroxybutyl acrylate, 3-acryloyloxyglycerin monomethacrylate,2-hydroxy-1,3-dimethacryloxypropane and 2-mercaptoethyl acrylate.

Out of the above compounds of the formula (2), preferred are compoundsrepresented by the following formula (3):

wherein R⁶ is a hydrogen atom or methyl group, and b is an integer of 2to 10, preferably 4 to 6, compounds represented by the following formula(4):

wherein R⁶ is a hydrogen atom or methyl group, R⁷ is —CH₂CH₂—,—-CH₂CH(CH₃)— or —CH(CH₃)CH₂—, and c is an integer of 2 to 9, preferably2 to 4, compounds represented by the following formula (5):

CH₂=CH—(CH₂)_(d)—O—(CH₂)_(b)—OH  (5)

wherein b is an integer of 4 to 10, and d is 0 or 1, and compoundsrepresented by the following formula (6):

CH₂=CH—(CH₂)_(d)—O—(OR⁷)—OH  (6)

wherein R⁷ is —CH₂CH₂—, —CH₂CH(CH₃)— or —CH(CH₃)CH₂—, c is an integer of2 to 9, and d is 0 or 1.

The compounds of the above formula (3) include 4-hydroxybutyl acrylateand 4-hydroxybutyl methacrylate.

The compounds of the above formula (4) include diethylene glycolmonoacrylate, tetraethylene glycol monoacrylate, polyethylene glycolmonoacrylate, tripropylene glycol monoacrylate, polypropylene glycolmonoacrylate, diethylene glycol monomethacrylate, tetraethylene glycolmonomethacrylate, polyethylene glycol ponomethacrylate, tripropyleneglycol monomethacrylate and olypropylene glycol monomethacrylate.

The compounds of the above formula (5) include 4-hydroxybutylallyl etherand 4-hydroxybutylvinyl ether.

The compounds of the above formula (6) include diethylene glycolmonoallyl ether and triethylene glycol monovinyl ether.

The above component (F-1) is used in an amount of 0.001 to 50 wt % basedon the total solid content of the base resin.

Component (F-2)

The component (F-2) is an unsaturated dibasic acid. Examples of thecomponent (F-2) include itaconic acid, succinic acid, malonic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, fumaric acid and maleic acid.

Component (F-3)

The component (F-3) is an cyclic anhydride of an unsaturated dibasicacid. Examples of the component (F-3) include succinic anhydride,glutaric anhydride, trimellitic anhydride, pyromellitic anhydride,phthalic anhydride and maleic anhydride.

Component (F-4)

The component (F-4) is an imide compound of an unsaturated dibasic acid.Examples of the component (F-4) include succinic acid imide, glutaricacid imide, phthalic acid imide and maleic acid imide.

Component (F-5)

The component (F-5) is a saturated polycarboxylic acid. Examples of thecomponent (F-5) include adipic acid and suberic acid.

Component (F-6)

The component (F-6) is an cyclic anhydride of a saturated polycarboxylicacid. Examples of the component (F-6) include cyclic anhydrides ofsaturated polycarboxylic acids as the component (F-5), such as adipicanhydride.

Component (F-7)

The component (F-7) is an imide compound of a saturated polycarboxylicacid. Examples of the component (F-7) include cyclic anhydrides of theabove saturated polycarboxylic acids (component (F-5)), such as adipicacid imide.

Component (F-8)

The component (F-8) is an amine. Examples of the component (F-8) includepolymethylene diamine, polyether diamine, diethylene triamine,iminobispropylamine, bishexamethylene triamine, diethylene triamine,tetraethylene pentaamine, pentaethylene hexaamine, pentaethylenehexamine, dimethylamino propylamine, aminoethyl ethanolamine,methyliminobispropylamine, menthanediamine, N-aminomethyl piperazine,1,3-diaminocyclohexane, isophorone diamine, metaxylene diamine,tetrachloroparaxylene diamine, methaphenilene diamine, 4,4-methylenedianiline, diaminodiphenylsulfone, benzidine, toluidine, diaminodiphenylether, 4,4′-thiodianiline, 4,4′-bis(o-toluidine)dianisidine, o-phenylenediamine, 2,4-toluene diamine, methylenebis(o-chloroaniline),diaminiditolylsulfone, bis(3,4-diaminophenyl)sulfone,2,6-diaminopyridine, 4-chloro-o-phenylene diamine,4-methoxy-6-methyl-m-phenylene diamine, m-aminobenzylamine,N,N,N′,N′-tetramethyl-1,3-butane diamine,N,N,N′,N′-tetramethyl-p-phenylene diamine, tetramethyl guanidine,triethanol amine, 2-dimethylamino-2-hydroxypropane,N,N′-dimethylpiperazine, N,N′-bis[(2-hydroxy)propyl]piperazine,N-methylmorpholine, hexamethylene tetramine, pyridine, piperazine,quinoline, benzyldimethylamine, α-methylbenzylmethylamine,2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethylol)phenol,N-methylpiperazine, pyrrolidine and morpholine.

An adduct of the above mine with an organic carboxylic acid, cyclicether, ketone, aldehyde or hydroquinone, or a condensate of the aboveamine may be used like the above amines.

Component (F-9)

The component (F-9) is urea and a formaldehyde adduct thereof.

Component (F-10)

The component (F-10) is an alkyl-substituted methylol melamine.

Component (F-11)

The component (F-11) is a compound having two or more OH groups or SHgroups. Examples of the component (F-11) include 1,4-butanediol,1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, ethylene glycol,diethylene glycol, triethylene glycol, tetraethylene glycol,polyethylene glycol, propylene glycol, tripropylene glycol,polypropylene glycol, trimethylol propane, neopentyl glycol, catechol,resorcinol, alkylene glycol, polyvinyl alcohol, polycaprolactone diol,polycaprolactone triol and polycaprolactone tetraol.

Component (F-12)

The component (F-12) is a compound having two or more epoxy groups.Examples of the component (F-12) include glycidyl ethers of polyhydricalcohols as the component (F-11).

Component (F-13)

The component (F-13) is a dicyandiamide, hydrazide, thiourea, guanidine,ethyleneimine, sulfoneamide or derivative thereof.

Component (F-14)

The component (F-14) is an organic silicon compound represented by thefollowing formula (7):

R⁸ ^(f)R⁹ _(o)Si(OR¹⁰)_(4−f−e)  (7)

wherein R⁹ is an alkyl group having 1 to 6 carbon atoms, aryl group,alkenyl group, halogenated alkyl group or halogenated aryl group, R₁₀ isa hydrogen atom, alkyl group having 1 to 4 carbon atoms, acyl group oralkylacyl group, R⁸ is selected from an alkyl group having 1 to 4 carbonatoms, halogenated alkyl group, aryl group and halogenated aryl grouphaving 6 to 12 carbon atoms, methacryloxyalkyl group having 5 to 8carbon atoms,ureidealkylene group having 2 to 10 carbon atoms, aromaticureidealkylene group, halogenated aromatic alkylene group andmercaptoalkylene group, f is 1, 2 or 3, and e is 0, 1 or 2, or a partialhydrolysate thereof.

The component (F-14) may be added in an amount of 100 parts or less byweight in terms of solid content based on 100 parts by weight of thetotal solid content of the base resin.

Examples of the compound of the above formula (7) includetrimethylmethoxysilane, triethylmethoxysilane, trimethylethoxysilane,triethylethoxysilane, triphenylmethoxysilane,diphenylmethylmethoxysilane, phenyldimethylmethoxysilane,phenyldimethylethoxysilane, vinyldimethylmethoxysilane,vinyldimethylethoxysilane, γ-acryloxypropyldimethylmethoxysilane,γ-methacryloxypropyldimethylmethoxysilane,γ-mercaptopropyldimethylmethoxysilane,γ-mercaptopropyldimethylethoxysilane,N-β(aminoethyl)γ-aminopropyldimethylmethoxysilane,γ-aminopropyldimethylmethoxysilane, γ-aminopropyldimethylethoxysilane,γ-glycidoxypropyldimethylmethoxysilane,γ-glycidoxypropyldimethoxyethoxysilane,β-(3,4-epoxycyclohexyl)ethyldimethylmethoxysilane,dimethyldimethoxysilane, diethyldimethoxysilane, dimethyldiethoxysilane,diethyldiethoxysilane, diphenyldimethoxysilane,phenylmethyldimethoxysilane, phenylmethyldiethoxysilane,vinylmethyldimethoxysilane, vinylmethyldiethoxysilane,γ-acryloxypropylmethyldimethoxysilane,γ-methacryloxypropyldimethyldimethoxysilane,γ-mercaptopropylmethyldimethoxysilane,γ-mercaptopropylmethyldiethoxysilane, N-β(aminoethyl-)γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane,γ-aminopropylmethyldiethoxysilane,γ-glycidoxypropylmethyldimethoxysilane,γ-glycidoxypropylmethoxydiethoxysilane,β-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane,methyltrimethoxysilane, ethyltrimethoxysilane, Gmethyltriethoxysilan,ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane,vinyl(β-methoxyethoxy)silane, γ-acryloxypropyltrimethoxysilane,γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-mercaptopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane,γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane,β-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane,γ-glycidoxypropyltriethoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, tetraethyl orthosilicateand tetramethyl orthosilicate.

The above components (F-1) to (F-14) may be added in a total amount of0.001 to 70 wt % based on the total solid content of the base resin.

The solvent for the composition for forming a hard coat layer is aglycol, aliphatic cyclic ketone, acetate or alcohol. Examples of theglycol include ethylene glycol monomethyl ether acetate, ethylene glycolmonoethyl ether acetate, ethylene glycol monopropyl ether acetate,ethylene glycol monobutyl ether acetate, propylene glycol monomethylether acetate, propylene glycol monoethyl ether acetate, propyleneglycol monopropyl ether acetate, propylene glycol monobutyl etheracetate, ethylene glycol dimethyl ether, ethylene glycol diethyl ether,ethylene glycol dipropyl ether, ethylene glycol dibutyl ether,diethylene glycol dimethyl ether, diethylene glycol diethyl ether,diethylene glycol dipropyl ether, diethylene glycol dibutyl ether,propylene glycol dimethyl ether, propylene glycol diethyl ether,propylene glycol monomethyl ether, ethylene glycol monoethyl ether andethylene glycol monobutyl ether. Examples of the aliphatic cyclic ketoneinclude cyclohexanone, o-methylcyclohexanone, m-methylcyclohexanone andp-methylcyclohexanone. Examples of the acetate include ethyl acetate,n-propyl acetate and n-butyl acetate. Examples of the alcohol includemethanol, ethanol, 1-propanol and 2-propanol. Solvent naphtha and methylethyl ketone may also be used as a solvent.

The solvent is used to ensure that the solids content of the compositionfor forming a hard coat layer should be 5 to 50 wt %.

Water is necessary to hydrolyze the component (C) and the component(F-14) and used in an amount 1.0 to 10 times the theoretical amount ofhydrolysis.

The composition for forming a hard coat layer may further contain aleveling agent, weatherability modifier, antistatic agent, colorant anddye for a cured film. Examples of the leveling agent out of theseinclude a copolymer of polyoxyalkylene and polydimethylsiloxane and acopolymer of polyoxyalkylene and fluorocarbon. The leveling agent isused in an amount of 0.001 to 10 parts by weight in terms of solidcontent in the composition for forming a hard coat layer.

The composition for forming a hard coat layer is applied to the surfaceof the substrate directly or the surface of the primer layer formed onthe surface of the substrate and cured. Coating is appropriatelyselected from dip coating, flow coating, spinner coating and spraycoating. Curing conditions include a temperature of 90 to 120° C. and atime of 30 minutes to 24 hours, for example. The optimum conditions arepreferably selected from these conditions.

The thickness of the hard coat layer is preferably 0.1 to 5 μm. When thethickness of the film is smaller than 0.1 μm, hardness may lower andwhen the thickness is larger than 5 μm, the film may crack. Thethickness of the hard coat layer is more preferably 0.5 to 5 μm.

A detailed description is subsequently given of a case where thetitanium oxide-containing urethane resin coat layer of the presentinvention is formed on the surface of the plastic lens substrate as aprimer layer.

Primer Layer

A solution composition for forming a primer layer (film) contains thefollowing components (1) to (4):

(1) 2 to 70 wt % in terms of solid content of a sol containing titaniumoxide or a composite oxide thereof having a particle diameter of 1.0 to100 nm dispersed in water or an organic medium;

(2) 0.1 to 10 wt % of an organic Co(II) compound;

(3) 10 to 87.9 wt % of a polyol; and

(4) 10 to 87.9 wt % of a polyisocyanate.

The components (1) and (2) has already described above.

Examples of the polyol as the component (3) include

olyester polyols, polyether polyols, acrylic polyols and polycarbonatepolyols. Out of these, polyester polyols are preferred.

The polyester polyols are obtained by carrying out the dehydrationcondensation of a polybasic acid and a compound having active hydrogen.Examples of the polybasic acid include organic acids such as isophthalicacid, phthalic acid, phthalic anhydride, hydrogenated phthalic acid,fumaric acid, dimerized linolenic acid, maleic acid and saturatedaliphatic dibasic acids having 4 to 8 carbon atoms. These polybasicacids may be used alone or in combination of two or more. Examples ofthe compound having active hydrogen include glycols such as ethyleneglycol, propylene glycol, butylene glycol, hexylene glycol anddiethylene glycol; adducts of trimethylolpropane, hexanetriol, glycerin,trimethylolethane, pentaerythritol, polycaprolactone diol,polycaprolactone triol, polycaprolactone tetraol and bisphenol A withethylene glycol and propylene; adducts of the above compounds withbromine; and diols having a chemical structure composed of4,4′-thiobisbenzenethiol. These compounds having active hydrogen may beused alone or in combination of two or more.

The above polyester polyols may be acquired as commercially availableproducts such as Demosphen Series (of Sumitomo-Bayer Co., Ltd.),Nipporan Series (of Nippon Polyurethane Co., Ltd.), Takerac Series (ofTakeda Chemical Industries, Ltd.), Adeca New Ace Series (of Asaki DenkaKogyo K. K.) and Barnoc (of Dainippon Ink and Chemicals, Inc.).

The polycarbonate polyols may be acquired as commercially availableproducts such as Nipporan 980 Series (of Nippon Polyurethane Co., Ltd.)and Carbodiol (of Toa Corporation.), the polyether polyols may beacquired as commercially available products such as Adecapolyether (ofAsahi Denka Kogyo K. K.), Actocall (of Takeda Chemical Industries, Ltd.)and PPG-Diol Series (of Mitsui Toatsu Chemicals Inc.) and the acrylicpolyols may be acquired as commercially available products such asTakerac (of Takeda Chemical Industries, Ltd.) and Acrydic (of DainipponInk and Chemicals, Inc.). They are preferably used to adjust thephysical properties of urethane resins.

The polyisocyanate may be an aliphatic polyisocyanate or polyisocyanatehaving an aromatic ring. The polyisocyanate is preferably diisocyanatehaving two or more isocyanate groups (NCO group) in the molecule.

Examples of the polyisocyanate include hexamethylene diisocyanate,1,3,3-trimethylhexamethylene diisocyanate, isophorone diisocyanate,4,4′-dicyclohexylmethane diisocyanate, xylylene diisocyanate,tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate,tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenateddiphenylmethane diisocyanate, 1,5-naphthalene diisocyanate andtetramethylxylylene diisocyanate. These polyisocyanates may be used as amodified product, isocyanurate, allophanate, burette, carbodiimide oradduct such as trimer.

The polyisocyanate may be blocked by a blocking agent. Examples of theblocking agent include acetylacetone, diethyl malonate, dimethylmalonate, 2,4-hexanedione, 3,5-heptanedione, acetooxime, butanoneoxime,methyl ethyl ketooxime and caprolactam. Out of these, β-diketone such asacetylacetone and methyl ethyl ketooxime are preferred.

The isocyanate blocked by a blocking agent can be synthesized by knowntechnologies such as methods described in British Patent No. 1442024,Polym. Sci. Technol., 36. 197 (1987), and Coating Technology 31, 161(1992).

When the polyisocyanate is an aromatic polyisocyanate such as xylylenediisocyanate or tetramethylxylene diisocyanate, it can be advantageouslyused as a modified product, adduct or prepolymer.

When the polyisocyanate is an aliphatic polyisocyanate, it is blocked byβ-diketone and advantageously used. Particularly when hexamethylenediisocyanate is used as a cyclic trimer blocked by β-diketone, theprimer composition can be advantageously provided as a one-part typecomposition.

The primer composition may contain the above polyol and polyisocyanatewhile they are not reacted with each other or may contain a prepolymeror thermoplastic (linear) polymer obtained by reacting the above polyoland polyisocyanate.

When the primer composition contains the above polyol and polyisocyanatewhile they are not reacted with each other, the ratio (NCO/OH) of thenumber of equivalents of the isocyanate group (NCO) of thepolyisocyanate to the number of equivalents of the hydroxyl group (OH)of the polyol is preferably in the range of 0.7 to 1.5. When the ratiois smaller than 0.7, the adhesion of the hard coat layer to the obtainedprimer layer may decrease and when the ratio is larger than 1.5, theprimer layer may whiten or the adhesion of the hard coat layer maylower. The (NCO/OH) ratio is more preferably in the range of 0.8 to 1.2.

In the primer composition, the weight percentages of the abovecomponents (1), (2), (3) and (4) are based on 100 wt % of the totalweight of all the components.

The amount of the component (1) is preferably 3 to 65 wt %, the amountof the component (2) is preferably 0.2 to 5 wt %, the amount of thecomponent (3) is preferably 12 to 84.8 wt %, and the amount of thecomponent (4) is preferably 12 to 84.8 wt %.

The primer composition may further contain the same oxide fine particle(component (D)) as in the above hard coat composition in an amount of 80wt % or less as required to approximate the refractive index of theprimer layer to that of the lens.

The primer composition may optionally contain a curing catalyst,leveling agent, lubricity modifier, weatherability modifier, antistaticagent, colorant, bluing agent and the like. The type and content of thecuring catalyst are the same as the curing catalyst for the abovecomposition for forming a hard coat layer.

The primer composition in the present invention is provided as anorganic solvent or aqueous solution. Examples of the organic solvent arethe same as those enumerated for the above hard coat, such as glycols,aliphatic cyclic ketones, acetates and alcohols. The solvent is used inan amount of 2 to 50 wt % in terms of solid content in the primercomposition.

The primer composition is applied to the surface of the substrate andcured. Coating is appropriately selected from dip coating, flow coating,spinner coating and spray coating. Preferred curing conditions include atemperature of 85 to 120° C. and a time of 15 minutes to 10 hours. Theoptimum conditions are preferably selected from the above conditions.

The thickness of the primer layer is preferably 0.5 to 5 μm. When thethickness is smaller than 0.5 μm, the effect of improving the impactresistance of a coated article is small and when the thickness is largerthan 5 μm, the hardness of the hard coat layer to be formed on theprimer layer may lower.

An anti-reflection layer which comprises a single-layer or multiplelayers of an inorganic material may be formed on the hard coat layer.This makes it possible to suppress the reflection of visible light andimprove visible light transmission and weatherability. Examples of theinorganic material include SiO, SiO₂, Si₃N₄, TiO₂, ZrO₂, Al₂O₃, MgF₂ andTa₂O₅. The anti-reflection film can be made thin by a vacuum depositionmethod or the like.

The substrate in the present invention may be a transparent substratemade from a plastic such as a polyurethane resin, methacrylic polymer,allyl polymer or copolymer thereof, or glass having a refractive indexof 1.50 or more. Examples of the substrate include substrates for use inoptical lenses such as spectacle lenses and camera lenses, displayelement filters, glass sheets for construction, auto window glass andlight covers for use in automobiles.

To produce the resin coated article of the present invention, asubstrate whose surface has been treated with an alkali, acid orsurfactant, which is polished with inorganic or organic fine particles,or which is subjected to a primer treatment, plasma treatment, coronatreatment or flame treatment may be used as the substrate to improve theadhesion of the coat layer to the lens substrate.

One preferred mode of the liquid composition for forming a primer layerfor the coated article of the present invention is a liquid compositionfor forming a primer layer which contains the following components (1)to (4):

(1) a sol containing titanium oxide or a composite oxide thereof havinga particle diameter of 1.0 to 100 nm dispersed in water or an organicsolvent;

(2) a Co(II) chelate compound or fatty acid compound,

(3) a polyester pblyol; and

(4) a polyisocyanate.

Preferably, the above component (1) is contained in an amount of 2 to 70wt %, the component (2) in an amount of 0.1 to 10 wt %, the component(3) in an amount of 10 to 87.9 wt % and the component (4) in an amountof 10 to 87.9 wt % in terms of solid content.

One preferred mode of the coated article of the present invention is aplastic lens comprising a substrate having a refractive index of 1.50 ormore and a hard coat layer which is essentially composed of a siliconresin, has a thickness of 0.1 to 5 μm and a refractive index of 1.48 ormore, and is formed on the surface of the plastic lens substratedirectly or through a primer layer, the hard coat layer comprising:

(1) 2 to 70 wt % of titanium oxide or a composite oxide thereof having aparticle diameter of 1.0 to 100 nm;

(2) 0.1 to 10 wt % of a Co(II) chelate compound or fatty acid compound;:

(3) 20 to 97.9 wt % of a silicon-based resin; and

(4) 0.001 to 10 wt % of a curing catalyst.

Another preferred mode of the coated article of the present invention isa plastic lens comprising a substrate having a refractive index of 1.50or more, a primer layer which is essentially composed of an urethaneresin and has a thickness of 0.5 to 5 μm and a refractive index of 1.48or more, and a hard coat layer which is essentially composed of asilicon resin, are formed on the surface of the substrate in the ordernamed, the primer layer comprising:

(1) 2 to 70 wt % of titanium oxide or a composite oxide thereof having aparticle diameter of 1.0 to 100 nm;

(2) 0.1 to 10 wt % of a Co(II) chelate compound or fatty acid compound;and

(3) 20 to 97.9 wt % of an urethane-based resin.

EXAMPLE

The following examples are provided for the purpose of furtherillustrating the present invention but are in no way to betaken aslimiting.

Preparation of Primer Coat Solutions 1 to 5

64 g of apolyester polyol comprising isophthalic acid and 1,6-hexanedioland having an average molecular weight of 940 and a hydroxyl group valueof 120 mgKOH/g and 65 g of a butyl acetate solution containing 75 wt %of a trimer of hexamethylene diisocyanate blocked by β-diketone wereprepared and mixed with 710 g of propylene glycol monomethyl ether andstirred until a uniform solution was obtained, 160 g of a compositeoxide sol 1 which consisted of TiO₂, Fe₂O₃ and SiO₂(TiO₂/Fe₂O₃/SiO₂=81/1/18 (weight ratio), titanium oxide was of ananatase type, dispersed in methanol, and had an average particlediameter of 10 nm and a nonvolatile content of 30%) was added, stirredand mixed until a uniform solution was obtained, and then 0.5 g of theFlorad FC-430 of 3M Co., Ltd. was added as a leveling agent and stirred.The obtained composition was designated as primer coat solution 1.

1 g of CO(II) acetylacetonato dehydrate was added to 1,000 g of theseparately prepared primer coat solution 1 and stirred to prepare aprimer coat solution 2.

31 g of a polyester polyol comprising isophthalic acid and adipic acid(molar ratio of 6:4), 1,6-hexanediol and trimethylolpropane and havingan average molecular weight of 650 and a hydroxyl group value of 260mgKOH/g, 68 g of a butyl acetate solution containing 75 wt % of a trimerof hexamethylene diisocyanate blocked by β-diketone and 634 g ofpropylene glycol monomethyl ether were stirred and mixed together untila uniform solution was obtained, 266 g of a composite oxide sol 2consisting of TiO₂, ZrO₂ and SiO₂ (TiO₂/ZrO₂/SiO₂=65/5/30 (weightratio), titanium oxide was of an anatase type, dispersed in methanol andhad an average particle diameter of 10 nm and a nonvolatile content of30%) was added, stirred and mixed until a uniform solution was obtained,and 0.5 g of the Florad FC-430 of 3M Co., Ltd. was added as a levelingagent and stirred. The obtained composition was designated as primercoat solution 3.

61 g of a polyester polyol consisting of isophthalic acid and3-methyl-1,5-pentanediol and having an average molecular weight of 490and a hydroxyl group value of 226 mgKOH/g, 118 g of a propylene glycolmethyl acetate solution containing 70 wt % of a trimer of hexamethylnediisocyanate blocked by β-diketone and 630 g of propylene glycolmonomethyl ether were stirred and mixed together until a uniformsolution was obtained, 187 g of a composite oxide sol 3 consisting ofTiO₂, ZrO₂ and SiO₂ (TiO₂/ZrO₂/SiO₂=79/1/20 (weight ratio), titaniumoxide was of a rutile type, dispersed in methanol and had an averageparticle diameter of 10 nm and a nonvolatile content of 30%) was added,stirred and mixed until a uniform solution was obtained, and 0.5 g ofthe Florad FC-430 of 3M Co., Ltd. was added as a leveling agent andstirred. The obtained composition was designated as primer coat solution4.

61 g of a polyester polyol consisting of adipic acid and3-methyl-1,5-pentanediol and having an average molecular weight of 485and a hydroxyl group value of 231 mgKOH/g, 119 g of a propylene glycolmethyl acetate solution containing 70 wt % of a trimer of hexamethylnediisocyanate blocked by β-diketone and 624 g of propylene glycolmonomethyl ether were stirred and mixed together until a uniformsolution was. obtained, 187 g of the above composite oxide sol 3 wasadded, stirred and mixed until a uniform solution was obtained, 2 g of aCo(II) salt of 2-ethyl-hexylic acid was added and stirred, and 0.5 g ofthe Florad FC-430 of 3M Co., Ltd. was added as a leveling agent andstirred. The obtained composition was designated as primer coat solution5.

Preparation of Hard Coat Solutions 1 to 9

235 g of the same composite oxide sol 1 as used in the preparation ofthe above primer coat solution 1 was weighed. 140 g of distilled waterwas added under agitation. 191 g of γ-glycidoxypropyltrimethoxysilaneand 42 g of tetramethoxysilane were gradually added. After the end ofaddition, they were stirred for another 2 hours. Thereafter, 373 g ofpropylene glycol monomethyl ether was added while the mixed solution wasstirred and then 2 g of tetraethylene glycol monomethacrylate was added.8 g of acetylacetone aluminum as a curing catalyst and 0.4 g of asilicone surfactant (L-7001 of Nippon Unicar Co., Ltd.) as a levelingagent were further added and stirred for 1 hour. The above mixedsolution was aged at room temperature for 48 hours to obtain a hard coatsolution 1.

235 g of the above composite oxide sol 1 was weighed. 140 g of distilledwater was added under agitation. 191 g ofγ-glycidoxypropyltrimethoxysilane and 42 g of tetramethoxysilane weregradually added. After the end of addition, they were stirred foranother 2 hours. Thereafter, 373 g of propylene glycol monomethyl etherwas added while the mixed solution was stirred and then 2 g oftetraethylene glycol monomethacrylate was added. 8 g of acetylacetonealuminum as a curing catalyst and 0.4 g of a silicone surfactant (L-7001of Nippon Unicar Co. Ltd.) as a leveling agent were further added andstirred for 1 hour. 2 g of Co(II) acetylacetonato dehydrate was stillfurther added and stirred. The above mixed solution was aged at roomtempetature for 48 hours to obtain a hard coat solution 2.

295 g of the above composite oxide sol 2 was weighed. 115 g of distilledwater was added under agitation. 178 g ofγ-glycidoxypropyltrimethoxysilane was gradually added. After the end ofaddition, it was stirred for another 2 hours. Thereafter, 378 g ofisopropyl alcohol was added while the mixed solution was stirred andthen 15 g of tetraethylene glycol monomethacrylate was added. 7 g ofacetylacetone aluminum as a curing catalyst and 0.4 g of a siliconesurfactant (L-7001 of Nippon Unicar Co., Ltd.) as a leveling agent werefurther added and stirred for 1 hour. The above mixed solution was agedat room temperature for 48 hours to obtain a hard coat solution 3.

295 g of the above composite oxide sol 2 was weighed. 115 g of distilledwater was added under agitation. 178 g ofγ-glycidoxypropyltrimethoxysilane was gradually added. After the end ofaddition, it was stirred for another 2 hours. Thereafter, 378 g ofisopropyl alcohol was added while the mixed solution was stirred andthen 15 g of tetraethylene glycol monomethacrylate was added. 7 g ofacetylacetone aluminum as a curing catalyst and 0.4 g of a siliconesurfactant (L-7001 of Nippon Unidar Co., Ltd.) as a leveling agent werefurther added and stirred for 1 hour. 4.6 g of Co(II) acetylacetonatodehydrate and 2.3 g of 4,4′-thiobis(3-methyl-6-t-butylphenol) were stillfurther added and stirred. The above mixed solution was aged at roomtemperature for 48 hours to obtain a hard coat solution 4.

A hard coat solution 5 was obtained in the same manner as the hard coatsolution 4 except that 6.9 g of a Co(II) salt of 2-ethyl-hexylic acidwas added in place of the Co(II) acetylacetonato dehydrate and4,4′-thiobis(3-methyl-6-t-butylphenol) in the preparation of the hardcoat solution 4.

261 g of the above composite oxide sol 3 was weighed. 140 g of distilledwater was added under agitation. 181 g ofγ-glycidoxypropyltrimethoxysilane was gradually added. Thereafter, 39 gof tetraethyl orthosilicate was added under agitation and then furtherstirred for 2 hours. Thereafter, 361 g of propylene glycol monomethylether was added while the mixed solution was stirred, and then 2 g oftetraethylene glycol monomethacrylate was added. 9 g of acetylacetonealuminum as a curing catalyst and 0.4 g of a silicone surfactant (L-7001of Nippon Unicar Co., Ltd.) as a leveling mixed solution was aged atroom temperature for 48 hours to obtain a hard coat solution 6.

After 1 kg of the above hard coat solution 6 was prepared separately, 2g of Co(II) acetylacetonato dihydrate was added and stirred for 1 hour.The above mixed solution was aged at room temperature for 48 hours toobtain a hard coat solution 7.

348 g of the above composite oxide sol 3 was weighed. 110 g of distilledwater was added under agitation. 148 g ofγ-glycidoxypropyltrimethoxysilane was gradually added and furtherstirred for 2 hours. Thereafter, 368 g of propylene glycol monomethylether was added while the mixed solution was stirred, and then 11 g oftetraethylene glycol monomethacrylate was added. 6 g of acetylacetonealuminum as acuring catalyst and 0.4 g of a silicone surfactant (L-7001of Nippon Unicar Co., Ltd.) as a leveling agent were further added andstirred for 1 hour. The above mixed solution was aged at roomtemperature for 48 hours to obtain a hard coat solution 8.

After 1 kg of the above hard coat solution 8 was prepared separately,5.0 g of a Co(II) salt of 2-ethyl-hexylic acid was added and stirred for1 hour. The above mixed solution was aged at room temperature for 48hours to obtain a hard coat solution 9.

Examples 1 to 8 and 12 to 14 and Comparative Examples 1 to 4

The above primer coat solutions 1 to 5 were each applied to thefollowing two different lens substrates by the following methods andcured by heating and then the above hard coat solutions 1 to 9 were eachapplied to the above substrates by the following dip coating and curedby heating. The evaluation results of the properties of the obtainedcoated lenses are shown in Table 2. The thickness and refractive index(nD) of each film measured by the following methods are shown inTable 1. The results of a weatherability test measured by the followingmethod are shown in Tables 3 and 4.

Lens Substrate:

The following lens substrates A and B were used.

substrate A: plastic spectacle lens made from a thiourethane resinhaving a refractive index of 1.594 and manufactured by molding andthermosetting the MR-6 monomer of Mitsui Toatsu Chemicals, Inc.

substrate B: plastic spectacle lens made from a thiourethane resinhaving a refractive index of 1.66.and manufactured by molding andthermosetting the MR-7 monomer of Mitsui Toatsu Chemicals, Inc.

application and curing methods of primer coat solution:

The lens substrate is immersed in a primer coat solution, pulled up at arate of 10 cm/min, dried at room temperature for about 10 minutes andheated at 95° C. for 30 minutes to cure a coating film.

application and curing methods of hard coat solution:

The lens substrate (or substrate with a cured primer layer) is immersedin a hard coat solution, pulled up at a rate of 15 cm/min, dried at roomtemperature for about 5 minutes and heated at 120° C. for 1 hour to curea hard coat layer.

Measurement of Film Thickness:

Each of the coat solutions is applied to a glass plate and is cured,part of the coating film is chipped off and the resulting leveldifference is measured to obtain the thickness of the film. It has beenconfirmed that whether the substrate is the above substrate A or B, thethickness of the obtained film remains the same as that of the aboveglass plate.

Measurement of Weatherability:

The appearance adhesion and hardness of a film after 60, 120, 180 and240 hours of irradiation are evaluated as follows using a xenonweather-ometer weatherability tester (black panel temperature of630°°C., water sprayed for 18 minutes every 2 hours, irradiationintensity of 0.35 W/m² at 340 nm).

appearance: observed with the eye and ranked as follows.

A-no change

B-part of the lens slightly cracks

C-about 1/3 of the area of the lens cracks

D-all the surface of the lens cracks adhesion: A cross-hatch test isconducted in accordance with a cross cut adhesion test JIS K5400. Thatis, 11 parallel lines are cut on the surface of the film in bothlongitudinal and transverse directions at intervals of 1 mm by a knifeto form 100 squares and Cellotape is affixed to the squares and thenpeeled off to count the number of squares adhered to the substrate fromwhich the film is not peeled. The proportion (%) of the number of thesquares to the total number of squares is taken as adhesion.

hardness: The film is rubbed with steel wool #0000 10 times under a loadof 1 kg to measure the scratching of the film based on the followingcriteria.

5: not scratched at all

4: slightly scratched

3: scratched

2: badly scratched

1: scratched to the substrate

TABLE 1 type of solution film thickness (μm) refractive index primer 11.1 1.59 primer 2 1.2 1.59 primer 3 1.1 1.66 primer 4 1.2 1.59 primer 51.2 1.59 hard coat 1 2.2 1.59 hard coat 2 2.2 1.59 hard coat 3 1.5 1.63hard coat 4 1.5 1.63 hard coat 5 1.5 1.63 hard coat 6 2.1 1.59 hard coat7 2.1 1.59 hard coat 8 2.1 1.63 hard coat 9 2.1 1.63

TABLE 2 lens primer hard coat No. substrate solution solution adhesionhardness Ex. 1 A 1 2 100% 5 Ex. 2 A 2 1 100% 5 Ex. 3 A 2 2 100% 5 Ex. 4A none 2 100% 5 Ex. 5 B 3 4 100% 4 Ex. 6 B 3 5 100% 4 Ex. 7 B none 4100% 4 Ex. 8 B none 5 100% 4 Ex. 12 A none 7 100% 5 Ex. 13 B 3 9 100% 4Ex. 14 B none 9 100% 4 C.Ex. 1 A 1 1 100% 5 C.Ex. 2 A none 1 100% 5C.Ex. 3 B 3 3 100% 4 C.Ex. 4 B none 3 100% 4

TABLE 3 weatherability test appear- appear- hard- ance adhesion hardnessance adhesion ness after 60 hours after 120 hours Ex.1 A 100 5 A 100 5Ex.2 A 100 5 A 100 5 Ex.3 A 100 5 A 100 5 Ex.4 A 100 5 A 100 5 Ex.5 A100 4 A 100 4 Ex.6 A 100 4 A 100 4 Ex.7 A 100 4 A 100 4 Ex.8 A 100 4 B100 4 C.Ex.1 A 100 5 A 100 5 C.Ex.2 A 100 5 A 100 5 C.Ex.3 A 100 4 B 1004 C.Ex.4 A 100 4 B 100 4 after 180 hours after 240 hours Ex.1 A 100 4 B100 2 Ex.2 B 100 3 C 100 2 Ex.3 A 100 4 B 100 2 Ex.4 A 100 4 B 100 2Ex.5 A 100 3-4 B 100 2 Ex.6 A 100 3-4 B 100 2 Ex.7 A 100 3-4 B 100 2Ex.8 A 100 3 B 100 2 C.Ex.1 B 0 2 D 0 1 C.Ex.2 B 0 2 C 0 1 C.Ex.3 C 0 2D 0 1 C.Ex.4 C 0 2 D 0 1

TABLE 4 weatherability test appearance adhesion hardness after 60 hoursEx. 12 A 100 5 Ex. 13 A 100 4 Ex. 14 A 100 4 after 120 hours Ex. 12 A100 5 Ex. 13 A 100 4 Ex. 14 A 100 4 after 180 hours Ex. 12 A 100 5 Ex.13 A 100 4 Ex. 14 A 100 4 after 240 hours Ex. 12 A 100 4 Ex. 13 A 1003˜4 Ex. 14 A 100 3˜4

Examples 1 to 8 and 12 to 14 and Comparative Examples 1 to 4 aresatisfactory in terms of appearance, film adhesion and film hardnessafter 120 hours of a weatherability test but differences in theseproperties is observed among them after 180 hours of the weatherabilitytest.

Film adhesion is satisfactory even after 240 hours in Examples 1 to 8and 12 to 14 but film adhesion is lost after 240 hours in ComparativeExamples 1 to 4,

When anatase type titanium oxide is used, film hardness is satisfactoryafter 180 hours in Examples 1 to 8 but it deteriorates after 180 hoursin Comparative Examples 1 to 4, When rutile type titanium oxide is used,film hardness is satisfactory after 240 hours in Examples 12 to 14, Whenanatase type titanium oxide is used, Examples 1 to 8 are superior infilm appearance to Comparative Examples 1 to 4, When rutile typetitanium oxide is used, both Examples and Comparative Examples aresatisfactory after 240 hours.

What is claimed is:
 1. A plastic lens comprising a plastic lenssubstrate having a refractive index of 1.50 or more and a hard coatlayer which is formed on the surface of the substrate directly orthrough a primer layer, the hard coat layer comprising: (1) 2 to 70 wt %of titanium oxide or a composite oxide thereof having a particlediameter of 1.0 to 100 nm, the titanium oxide containing at least onetitanium oxide selected from the group consisting of rutile typetitanium oxide and anatase type titanium oxide in an amount of 50 wt %or more; (2) 1 to 10 wt % of a chelate compound or fatty acid saltcontaining Co(II); (3) 20 to 97.9 wt % of a silicon resin, and (4) 0.001to 10 wt % of a curing catalyst selected from the group consisting ofalkali metal salts and ammonium salts of carboxylic acids, metal saltsand ammonium salts of acetylacetone, metal salts of ethyl acetoacetate;metal salts coordinated with acetylacetone and ethyl acetoacetate, metalsalt hydrates of ethylene diamine, primary to tertiary amines,polyalkylene amines, sulfonates, magnesium perchlorate, ammoniumperchlorates, and combinations of these compounds and organic mercaptanor mercaptoalkylenesilane, but being different from said chelatecompound or fatty acid salt containing Co(II), and having a refractiveindex of 1.48 or more and a thickness of 0.5 to 5 μm, the weightpercentages of the above components (1), (2) and (3) being based on 100wt % of the total weight of the components (1), (2) and (3), and theweight percentage of the above component (4) being based on the totalweight of the above components (1), (2) and (3).
 2. The plastic lens ofclaim 1, wherein the hard coat layer further comprises an antioxidanthaving a C—S—C structure in an amount of 0.1 to 5 wt % based on the hardcoat layer.
 3. The plastic lens of claim 1, wherein the chelate compoundor fatty acid salt containing Co(II) is acetylacetonate Co(II) or Co(II)ethylhexylate.
 4. The plastic lens of claim 1, wherein the primer layercontains an urethane resin as a resin component and has a refractiveindex of 1.48 or more.
 5. The plastic lens of claim 1 which further hasan anti-reflection layer on the exterior surface of the hard coat layer.